1. Field of the Invention
The present invention relates generally to a light fixture, and more particularly to a light fixture, which is capable of automatically controlling to maintain stably an illuminance of incident light on a desired spot/area in an active smart manner, wherein the illuminance is generally shown in “lux” unit, and a measurement of luminus flux over a unit of area.
2. The Prior Arts
A light emitting module, generally called a light source, when electrical power is supplied to thereto and after the electrical power is converted into light power, is capable of radiating a light beam so as to illuminate a targeted spot/area.
The currently available light fixtures, a majority of which possess only one stage or a single function, that is fully illuminating the targeted spot/area when switched on or the targeted spot/area is not illuminated at all when switched off. Such type of light fixture performs only in a single stage and hence results in several problems, the targeted spot/area is too brightly illuminated, and thereby causing undesired waste of electrical power or the targeted spot/area is dimly illuminated. To avoid the problem of too brightly illuminated, one can reduce the number of light bulbs or lamps in the light fixture, such as only employing two light bulbs instead of three and so forth.
Later, some manufacturers have developed light fixtures, which are capable of providing lighting or illumination in multiple stages via externally controlled circuit, like 75%, 50%, 25% of illumination or brightness such that the user can select the required amount of illumination. Another way is the stepless control of illumination, which function can be achieved by manipulating a rotary knob or an electronic controller for automatically selecting the required amount of illumination. A common problem is resulted when the above-mentioned two types of light fixtures are implemented, that is the light fixture is required to be actively manipulated by the user when the external environmental illumination varies, those light fixtures can only provide degree of illumination or dimness according to the currently set illuminance
Moreover, the light fixtures are again improved to overcome the existing disadvantages, that is sensor or detection devices are implemented so as to automatically adjust and modulate the illumination of a desired spot/area. In other words, the adjustment is conducted not relative to the light source or the illuminance of the focusing area. Under this condition, the sensor device is unable to automatically and effectively detect and fix the illuminance of the focusing area, thereby leading the wrong determination of the afterward performance, such as automatically increasing and decreasing the illumination or irregular increasing and decreasing the illumination. When such events occur, the viewer has to bear a great visual burden, i. e., vision damage and this can be avoided if the viewer is a youth, or the vision damage is not realized or noticed by the viewer if he is too young to know the defects. Of late, the average vision of majority of citizens is vividly and gradually getting worse day by day.
Therefore, the major object of the inventor of the present application or the manufacturers in the similar field is in an urgent desire to find out how to eliminate the above-mentioned disadvantages.